Simple-to-operate, budget reverb units are no longer a novelty, but DOD are really going for the entry-level user with their 512: it's very easy to use, provides plenty of stock effects, and is eminently affordable.

As you can see from the photo, the 512 favours the rotary switch approach for patch selection. Alesis pioneered this idea, and later added another switch, to access 16 variations on each of the 16 presets. DOD have taken this idea further, adding a bank switch, to double the number of options to 512 -- hence the name of the unit. To increase flexibility, DOD have also provided a couple of controls, labelled Parameter 1 and Parameter 2, which access two key parameters for each effect type.

DESCRIPTION

Housed in a 1U case and powered by the familiar external PSU, the 512 has stereo inputs and outputs on unbalanced jacks, no MIDI, and no power switch. It does, however, have an integral (simple but functional) noise gate, the threshold of which is controlled by a screwdriver-adjustable pot on the rear panel. Separate knobs provide control of input/output levels and mix, and there's a simple LED metering system for setting the input level.

Electrically, the 512 looks quite impressive, with a 90dB signal-to-noise ratio, 16-bit/44.1kHz sampling, and a 20Hz-16kHz audio bandwidth. The input may be adjusted to accommodate both pro and semi-pro signal levels, though the input impedance is too low to use directly with a passive electric guitar.

The 32 basic effects combinations offered by the unit are accessed via the 16-way Effect switch and the Bank button, while a Preset switch selects between 16 variations. An additional switch position acts as a bypass mode. This works well, except for the tiny lettering around the Effect switch, which had me peering with a torch from about eight inches away!

Bank A holds 16 different single effects, comprising various reverb types, mono and stereo delays, chorus, flange, phasing, panning and pitch shifting. If a reverb, for example, is selected, the two Parameter controls mentioned earlier vary the stereo width and the EQ, and the 16 variations provide different decay times. In delay mode, you can control decay time (up to 740ms in mono mode), and regeneration, while modulation effects can have their rate and EQ controlled (though I rather expected that rate and depth would be controllable). There's also a pitch-shifter, which can be used either for detuning, or for pitch-shifting by up to an octave in either direction, in semitone steps. As with the modulation effect, EQ control is provided.

Bank B combines the modulation effects with either reverb or delay; the user can control delay/decay time, and the balance between the two effects.

PERFORMANCE

My feelings about the 512 are rather mixed; I like the operating system, and the modulation and delay effects are actually very good, but I find the reverbs disappointing in comparison with some other budget units. There's very little difference between the different reverb types, other than tonality and decay time, and all, to me, sound rather coloured or spring-like -- usually a sign of insufficient processing power. The spring reverb emulation, on the other hand, is quite authentic. It's not that DOD/Digitech can't make good reverbs, because Digitech's pro products are exceptionally good -- it's simply that high-quality reverb usually requires serious hardware, and the compromises necessary to achieve the low price of the 512 are starting to show.

If you already have a decent reverb unit and simply want good chorus, flange and delay combinations, the DOD 512 begins to look like a better bet, as all the modulations and delays are clean and crisp, with a nice sense of width. The pitch-shifter is also surprisingly well behaved for such a budget unit, though as ever, it still needs to be mixed with some dry signal to be really convincing. The octave-down shift is particularly clean and works well with vocals. Inevitably, there is some delay associated with the pitch-shift effect, but that's part of the deal if you don't want an unduly glitchy result.

CONCLUSION

The verdict has to be that the 512 is a pretty good all-rounder for the money, with its reverbs being the only area of obvious compromise. If your main need is for a reverb, look elsewhere. Alternatively, if you can stretch to the extra £50, the Digitech Studio Twin (see review in September's SOS) still keeps the cost under control but improves on the reverb quality. But if you simply want a basic second effects unit to add to your flexibility, the 512 is worth listening to.